Mendeley import: Add "Other…" button for selecting another DB

E.g., for selecting a DB from a backup

Addresses #1451

chrome/content/zotero/import/importWizard.js

@@ -57,14 +57,38 @@ var Zotero_Import_Wizard = {
 	},
 	
 	
+	/**
+	 * When a file is clicked on in the file list
+	 */
 	onFileSelected: async function () {
 		this._wizard.canAdvance = true;
 	},
 	
 	
+	/**
+	 * When the user clicks "Other…" to choose a file not in the list
+	 */
+	chooseMendeleyDB: async function () {
+		const nsIFilePicker = Components.interfaces.nsIFilePicker;
+		var fp = Components.classes["@mozilla.org/filepicker;1"]
+			.createInstance(nsIFilePicker);
+		fp.init(window, Zotero.getString('fileInterface.import'), nsIFilePicker.modeOpen);
+		fp.appendFilter("Mendeley Database", "*.sqlite"); // TODO: Localize
+		var rv = fp.show();
+		if (rv != nsIFilePicker.returnOK) {
+			return false;
+		}
+		this._file = fp.file.path;
+		this._wizard.canAdvance = true;
+		this._wizard.advance();
+	},
+	
+	
 	onFileChosen: async function () {
-		var index = document.getElementById('file-list').selectedIndex;
+		if (!this._file) {
+			let index = document.getElementById('file-list').selectedIndex;
 			this._file = this._dbs[index].path;
+		}
 		this._disableCancel();
 		this._wizard.canRewind = false;
 		this._wizard.canAdvance = false;

chrome/content/zotero/import/importWizard.xul

@@ -42,6 +42,9 @@
 				<listcol/>
 			</listcols>
 		</listbox>
+		<hbox>
+			<button label="&zotero.general.other;" oncommand="Zotero_Import_Wizard.chooseMendeleyDB()"/>
+		</hbox>
 	</wizardpage>
 	
 	<wizardpage pageid="page-progress"

chrome/locale/en-US/zotero/zotero.dtd

@@ -16,6 +16,7 @@
 <!ENTITY zotero.general.loading "Loading…">
 <!ENTITY zotero.general.close                              "Close">
 <!ENTITY zotero.general.minimize                           "Minimize">
+<!ENTITY zotero.general.other                              "Other…">
 
 
 <!ENTITY zotero.errorReport.title							"Zotero Error Report">

chrome/skin/default/zotero/importWizard.css

@@ -37,8 +37,11 @@ listbox, #result-description {
 	font-size: 13px;
 }
 
+button {
+	font-size: 13px;
+}
+
 #result-report-error {
 	margin-top: 13px;
 	margin-left: 0;
-	font-size: 13px;
 }